>echo 127.0.0.1:12345 | perl -MRegexp::Common=net -lne 'print $_ for /$RE{net}{IPv4}:?\d{0,4}/g'
127.0.0.1:1234
>echo 127.0.0.1239999 | perl -MRegexp::Common=net -lne 'print $_ for /$RE{net}{IPv4}:?\d{0,4}/g'
127.0.0.1239999